<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
		<script src="js/vue.js" type="text/javascript" charset="utf-8"></script>
	</head>
	<body>
		
		<div id="app">
			<button @click="add1">add 1</button><br />
			this button has been click 	{{counter}} times. 
			
			<hr />
			
			<button @click="counter += 1">add 1</button><br />
			this button has been click 	{{counter}} times. 
			
			
		</div>
		
	</body>
</html>

<script type="text/javascript">
	var vm  = new Vue({
		el:'#app',
		data:{
			counter: 0
		},
		methods:{
			add1: function(){
				this.counter += 1;
			}
		}
	})
</script>